The issue is that with such a break, I bet you won't have much of a guild to come back to... what kept my guild together was that we constantly logged in every day and did stuff (that kept bonding us and creating this "I should really be online"-feeling)... When we had a first longer break (when people unsubbed to come back later),,, not even 50% came back... most came to check up but had grown out of the "I must login"-feeling and left raiding completely and now (2 years later) ZERO is playing (including myself).
Point being: Breaks are dangerous for Blizzard, people start realizing there is a life outside WoW and they leave and never comes back... So faster expansions/patches or Blizzard will lose massive amount of players, permanently!